Who knew? Jennifer Garner's stunning Versace gown at this year's Oscar ceremony had an extremely complex (and uncomfortable) underwear situation going on underneath!

During her appearance on Jimmy Fallon's Tonight Show on Wednesday, March 16, Ben Affleck's ex avoided talking about her divorce — opting instead to lift the lid on the intimate details of Oscar undergarments.

Gesturing to a photograph of herself in the stunning, black, floor-length gown, Garner revealed she had a full metal corset going on under the outfit — and revealed that bathroom trips in that kind of underwear are somewhat problematic!

"You see I have a waist right here?" Garner asked her host. "I don't have one in real life anymore … but what they do is they move your organs around.… There was a metal corset and it [took] two Italian people, who were talking very quickly, and the next thing you know, my ribs were compressed. These people move your ribs, and they move your liver out of the side and they pop you in," she said, laughing.

Four hours later, while watching the show with a close girlfriend, Garner's body started to rebel against the tight metal corset. "You step into a bodysuit first … like a leotard, but it's a thong. So I was in that, and we were watching the Academy Awards … and suddenly my ribs started to panic. Everything in here started to freak out," she continued.

"[My friend] was like, 'If you stand up, they'll think you're Kanye West, they'll think you're protesting. You can't stand up!'"

So Garner managed to stay put until the commercial break, when she suddenly realized she had to go to the bathroom.

"We go into the bathroom because she's going to have to hold something up. It's not pretty, but I just feel like you should know the truth about these things," Garner told Fallon, who was starting to look a bit embarassed.

"The connection of the bodysuit, because it had a hook-and-eye situation, was in an intimate position. It was, like, in, my vagine," she said, while Fallon squirmed!

“I couldn't reach it, so I said to my friend, 'I don't know what's going to happen, but I think you've got to get this,'" she went on.

"She's a good friend," Garner added. "She said, 'If this has to be done, it has to be done, but listen, I want you to give it a good college try!'"

Watch the whole hilarious conversation in the video above!

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